Lithospheric mantle heterogeneity beneath the Siberian craton: Evidence from garnet xenocryst database with implications for kimberlite compositions
Permanent lenke
https://hdl.handle.net/10037/36490Dato
2023-11-22Type
Journal articleTidsskriftartikkel
Peer reviewed
Forfatter
Kostrovitsky, S.I.; Tappe, Sebastian; Yakovlev, D.A.; Ivanov, A.S.; Spetsius, Z.V.; Ashchepkov, I.V.Sammendrag
It is reasonable to assume that relatively thin cratonic mantle lithosphere beneath the three anomalous kimberlite fields underwent intense metasomatic overprinting by melts and fluids injected from the underlying asthenosphere, which changed the compositions of peridotitic garnets significantly. An interpretation of the data presented in this study is that the generally high TiO2 contents of kimberlites in the northern YaKP (>1.5 wt% TiO2) are a primary magmatic feature of asthenospheric origin because the lithospheric mantle traversed by these kimberlite magmas is TiO2 depleted. We propose a model in which the relatively thin SCLM of the northern Siberian craton provided less opportunity for high-TiO2 asthenospheric kimberlite melts to interact and change compositions on their way to the Earth’s surface. The high-TiO2 kimberlites of the northern YaKP may thus represent a good approximation of the primary compositions of natural kimberlite melts.